His opponent, Soumaila Cissé, conceded defeat and went to see the victor before the final result was officially announced. In the aftermath of the vote, the international community promised the country substantial support. Surely any politician would dream of coming to power under such conditions. Everything seemed to have worked out perfectly when Keita was officially proclaimed president of a country that was recently on the verge of collapse.

During the campaign Keitaplayed on the nationalist fervour of his compatriots, who were confused by the loss of the north of the country to Tuareg rebels and Islamists and its subsequent recovery, mainly thanks to foreign armies.

Despite having been in politics for two decades, as well as being a former prime minister and speaker of the national assembly, Keita managed to embody a break with the past.

Bert Koenders, head of the UN Multidimensional Integrated Stabilisation Mission in Mali, is clear about the challenges facing the new government. "The country is moving forward, law and order are gradually being restored," he said. "Now it is up to the president-elect to deploy policies which prevent the crisis from recurring. Mali needs a new social contract, reform of the army, reconstruction of the apparatus of state and a drive to wipe out corruption."

He may have promised to be the "president of reconciliation", but Keita is quite prepared for the cut and thrust of democracy. "[He] wants a government that rules and an opposition that opposes. He didn't fight the fake consensus … that prevailed under [the previous] President Amadou Toumani Touré, only to restore the same system," says his long-standing comrade Albert Bourgi.

Though he dismisses the idea of a government of national unity, Keita will certainly have to come to terms with the divergent forces that brought him to power, starting with the army. During the campaign the leader of the junta that toppled Touré last year, Captain Amadou Sanogo, came out in support of Keita. He was recently promoted to the rank of four-star general. But the president's advisers categorically deny any secret agreement with the authors of the military takeover in March 2012.

Several religious leaders, including Mahmoud Dicko, the conservative head of the High Islamic Council, campaigned for Keita. Here again, his advisers promise that Mali will remain a secular state.

Keita has promised to continue along these lines, but his campaign hinged on national honour and dignity, pandering to public opinion in the south openly hostile to any understanding with the forces that plunged Mali into chaos. His real intentions are far from clear. Will he initiate the devolution process advocated by international funding agencies or build up a strong central government?

In the immediate future the president is not short of cash – the international community having promised more than $4bn. That's more than enough to launch many development projects – and fuel corruption.

• Oumar Tatam Ly, a former special adviser at the Central Bank of West African States, was named Mali's prime minister last week. Ly's cabinet includes a post focused on reconciliation and development of the country's north.

This article appeared in Guardian Weekly, which incorporates material from Le Monde